1. API Standard 6X: API/ASME Design Calculations New Draft Standard under Subcommittee 6

2. Task Group Membership • John Fowler – On-Line Resources - Chairman • Jim Britton – Cameron – 17D and 16C • Paul Bunch – Cameron – 16A and 17D • Jean Brunjes – GE – 6A • Bill Carbaugh – GE – 16A • Maynard Chance – West Engineering – All specs • Chris Johnson - NOV – 16A • Jim Kaculi – DrilQuip – 17D • Chris Kocurek – Cameron – 17D • John McCaskill - Expro – 16C • Nigel McKie – FMC – 17D • Mark Miser – DNV – All specs • Ramon Sanpredro – Stress Engineering – all specs • AlirezaShirani – GE – All specs

3. History and Objective • API 6A, 16A, and 16C referenced the ASME Code Section VIII Division 2, 2004 Edition, Appendix 4. • Since referencing an obsolete spec is awkward, an Annex (Annex I) was prepared for 16A capturing the method from that ASME Appendix. • Subcommittee 6 proposed that the method be put in a separate document to assure uniformity.

4. Task Group Charge • Create a new API standard documenting the rules of the ASME Code, based on Annex I. • Problem: 16A and 6A used different allowable stresses.

5. Resolution • The task group consensus was to use the rules of 16A, since going to the slightly more conservative 6A rules would penalize 16A/16C users who had designed to higher allowable stresses. • The 90% of Sy used in 16A and 16C is the same as the limit in the 2004 ASME Code Section VIII Division 2 • Using only the yield strength as a basis follows Section VIII Division 3 practice.

6. Changes to Annex I • Several revisions were made to the Annex I document to clarify the requirements, including several changes to the wording.. • Information of elastic-plastic collapse was added to the document. ASME Appendix 4 had referred to a method in Appendix 6 on experimental stress analysis. • The uses of limit analysis and elastic/plastic analysis were clarified. • The requirement on the sum of the three principal stresses was clarified as to the calculation basis.

7. Follow-on actions after publication of the new Standard • Specifications 6A, 16A and 16C should revise their design section to direct the designer to this new standard instead of the 2004 Code. • This may require several changes in the body of the specifications. • Since 17D refers to 6A for design requirements, no change is needed. • The1004 ASME Code Section VIII Division 2 can be removed as a referenced standard, and Standard 6X added.

8. Status of the draft Standard • The TG has finalized the draft and agreed it is ready for ballot. • API will edit the document into standard API format and return it to the TG for review. • After review the draft standard will be sent out for ballot by SC6. • SC 16 and SC 17 will solicit comments from their member companies, which will be considered along with those from SC6 members.